A Jeep driver believes a BP gas station was overcharging him for gasoline. “It was still going and I put almost 15 gallons of gas in that Jeep, I had over a quarter tank of gas already in it. One such reason is that “that actual fuel tank capacity can vary as much as 3 percent” from a car’s stated capacity. Slow Gas Pumps: Maintenance NeededIt’s worth mentioning that the Jeep driver stated several times that the fuel pump was dispensing gas very slowly. Fuel Logic also writes that faulty or broken fuel pumps can indeed lead to “incorrect flow rate readings.”